refactor: stage theme saves w/ atomic rename; add finalize/discard persistence tests

src/fe-gtk/theme/tests/test-theme-runtime-persistence.c

@@ -19,6 +19,12 @@ struct zoitechatprefs prefs;
 
 static char *test_home_dir;
 
+static char *
+test_home_path (const char *file)
+{
+	return g_build_filename (test_home_dir, file, NULL);
+}
+
 static gboolean
 read_line_value (const char *cfg, const char *key, char *out, gsize out_len)
 {
@@ -97,6 +103,12 @@ cfg_put_int (int fh, int value, char *var)
 	return write (fh, line, (size_t) len) == len;
 }
 
+char *
+get_xdir (void)
+{
+	return test_home_dir;
+}
+
 int
 zoitechat_open_file (const char *file, int flags, int mode, int xof_flags)
 {
@@ -145,7 +157,7 @@ read_colors_conf (void)
 	gsize length = 0;
 	gboolean ok;
 
-	path = g_build_filename (test_home_dir, "colors.conf", NULL);
+	path = test_home_path ("colors.conf");
 	ok = g_file_get_contents (path, &content, &length, NULL);
 	g_free (path);
 	g_assert_true (ok);
@@ -222,7 +234,7 @@ test_loads_legacy_color_keys_via_migration_loader (void)
 	gboolean ok;
 
 	setup_temp_home ();
-	path = g_build_filename (test_home_dir, "colors.conf", NULL);
+	path = test_home_path ("colors.conf");
 	ok = g_file_set_contents (path, legacy_cfg, -1, NULL);
 	g_free (path);
 	g_assert_true (ok);
@@ -336,6 +348,50 @@ test_gtk_map_uses_theme_defaults_until_custom_token_is_set (void)
 	g_assert_true (colors_equal (&values.foreground, &custom));
 }
 
+
+static void
+test_save_finalize_replaces_colors_conf_atomically (void)
+{
+	char *path;
+	char *temp_path = NULL;
+	char *cfg = NULL;
+	gboolean ok;
+
+	setup_temp_home ();
+	path = test_home_path ("colors.conf");
+	ok = g_file_set_contents (path, "theme.mode.light.token.mirc_0 = 0000 0000 0000\n", -1, NULL);
+	g_assert_true (ok);
+
+	theme_runtime_load ();
+	g_assert_true (theme_runtime_save_prepare (&temp_path));
+	g_assert_nonnull (temp_path);
+	g_assert_nonnull (g_strrstr (temp_path, "colors.conf.new."));
+	g_assert_true (g_file_test (temp_path, G_FILE_TEST_EXISTS));
+	g_assert_true (theme_runtime_save_finalize (temp_path));
+	g_assert_false (g_file_test (temp_path, G_FILE_TEST_EXISTS));
+	ok = g_file_get_contents (path, &cfg, NULL, NULL);
+	g_assert_true (ok);
+	g_assert_nonnull (g_strstr_len (cfg, -1, "theme.palette.semantic_migrated = 1"));
+	g_free (cfg);
+	g_free (temp_path);
+	g_free (path);
+}
+
+static void
+test_save_discard_unlinks_temp_file (void)
+{
+	char *temp_path = NULL;
+
+	setup_temp_home ();
+	theme_runtime_load ();
+	g_assert_true (theme_runtime_save_prepare (&temp_path));
+	g_assert_nonnull (temp_path);
+	g_assert_true (g_file_test (temp_path, G_FILE_TEST_EXISTS));
+	theme_runtime_save_discard (temp_path);
+	g_assert_false (g_file_test (temp_path, G_FILE_TEST_EXISTS));
+	g_free (temp_path);
+}
+
 static void
 test_save_writes_only_custom_token_keys (void)
 {
@@ -368,6 +424,10 @@ main (int argc, char **argv)
 			 test_gtk_map_colors_blend_with_palette_without_transparency);
 	g_test_add_func ("/theme/runtime/gtk_map_uses_theme_defaults_until_custom_token_is_set",
 			 test_gtk_map_uses_theme_defaults_until_custom_token_is_set);
+	g_test_add_func ("/theme/runtime/save_finalize_replaces_colors_conf_atomically",
+			 test_save_finalize_replaces_colors_conf_atomically);
+	g_test_add_func ("/theme/runtime/save_discard_unlinks_temp_file",
+			 test_save_discard_unlinks_temp_file);
 	g_test_add_func ("/theme/runtime/save_writes_only_custom_token_keys",
 			 test_save_writes_only_custom_token_keys);
 	return g_test_run ();

src/fe-gtk/theme/theme-runtime.c

@@ -4,6 +4,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <errno.h>
 
 #ifdef WIN32
 #include <io.h>
@@ -515,86 +516,61 @@ gboolean
 theme_runtime_save_prepare (char **temp_path)
 {
 	int fh;
-	const char *temp_name;
+	char *temp_name;
+	const char *config_dir;
 
 	if (!temp_path)
 		return FALSE;
 
-	temp_name = "colors.conf.new";
-	fh = zoitechat_open_file (temp_name, O_TRUNC | O_WRONLY | O_CREAT, 0600, XOF_DOMODE);
-	if (fh == -1)
+	config_dir = get_xdir ();
+	if (!config_dir)
 		return FALSE;
 
+	temp_name = g_build_filename (config_dir, "colors.conf.new.XXXXXX", NULL);
+	fh = g_mkstemp (temp_name);
+	if (fh == -1)
+	{
+		g_free (temp_name);
+		return FALSE;
+	}
+
 	if (!theme_runtime_save_to_fd (fh))
 	{
 		close (fh);
+		g_unlink (temp_name);
+		g_free (temp_name);
 		return FALSE;
 	}
 
 	if (close (fh) == -1)
+	{
+		g_unlink (temp_name);
+		g_free (temp_name);
 		return FALSE;
+	}
 
-	*temp_path = g_strdup (temp_name);
+	*temp_path = temp_name;
 	return TRUE;
 }
 
 gboolean
 theme_runtime_save_finalize (const char *temp_path)
 {
-	int src_fh;
-	int dst_fh;
-	char buffer[4096];
-	ssize_t read_len;
+	char *config_path;
 
 	if (!temp_path)
 		return FALSE;
 
-	src_fh = zoitechat_open_file (temp_path, O_RDONLY, 0, XOF_DOMODE);
-	if (src_fh == -1)
-		return FALSE;
-
-	dst_fh = zoitechat_open_file ("colors.conf", O_TRUNC | O_WRONLY | O_CREAT, 0600, XOF_DOMODE);
-	if (dst_fh == -1)
+	config_path = g_build_filename (get_xdir (), "colors.conf", NULL);
+#ifdef WIN32
+	g_unlink (config_path);
+#endif
+	if (g_rename (temp_path, config_path) == -1)
 	{
-		close (src_fh);
+		g_free (config_path);
 		return FALSE;
 	}
-
-	while ((read_len = read (src_fh, buffer, sizeof (buffer))) > 0)
-	{
-		ssize_t offset;
-
-		offset = 0;
-		while (offset < read_len)
-		{
-			ssize_t written;
-
-			written = write (dst_fh, buffer + offset, (size_t) (read_len - offset));
-			if (written <= 0)
-			{
-				close (src_fh);
-				close (dst_fh);
-				return FALSE;
-			}
-			offset += written;
-		}
-	}
-
-	if (read_len < 0)
-	{
-		close (src_fh);
-		close (dst_fh);
-		return FALSE;
-	}
-
-	if (close (src_fh) == -1)
-	{
-		close (dst_fh);
-		return FALSE;
-	}
-
-	if (close (dst_fh) == -1)
-		return FALSE;
+	g_free (config_path);
 
 	return TRUE;
 }
@@ -602,14 +578,10 @@ theme_runtime_save_finalize (const char *temp_path)
 void
 theme_runtime_save_discard (const char *temp_path)
 {
-	int fh;
-
 	if (!temp_path)
 		return;
 
-	fh = zoitechat_open_file (temp_path, O_TRUNC | O_WRONLY | O_CREAT, 0600, XOF_DOMODE);
-	if (fh != -1)
-		close (fh);
+	g_unlink (temp_path);
 }
 
 gboolean